Photo1: Properly installed carpet tile can have an almost “seamless” appearance. (Photo by Christopher Capobianco)

Photo 2: This carpet tile installation had gaps caused by a failure to install the material snug up to the wall.  Luckily the problem was easily corrected. (Photo by Christopher Capobianco)

I’ve been doing “Lets Talk Resilient” here in FCI since 2003 and this is the first time I have gotten to talk about “fuzzy stuff.” What a nice change of pace.  It fits in well with a theme I have covered here before - alternatives for resilient floor installers who are trying to expand their business. I have mentioned floating floors and glue-down wood flooring as well as some of the more technical resilient products like cork, linoleum and stair treads.  Carpet tile installation has many of the same attributes as resilient floors so installers can easily expand into this part of the business, which is a good thing because this category is growing fast in the commercial sector.

Much of what you need to pay attention to for installing carpet tile is the same as when doing resilient floor tile - substrate preparation, moisture testing, adhesive selection and job layout.

Photo 3: This carpet tile installation had gaps caused by a failure to install the material snug up to the wall.  Luckily the problem was easily corrected. (Photo by Christopher Capobianco)

Common wisdom is that you don’t have to worry nearly as much about a smooth substrate for carpet as you do with resilient floor products.  I don’t disagree that carpet is a lot more forgiving of telegraphing but the floor still has to be relatively flat and smooth.  Any high spots or dips in the substrate will affect the integrity of the floor, and although they are not as glaringly obvious it still will be a call back if the owner notices it! Better to take care of these before the job begins. The surface smoothness is another detail to look at.  Even though a rough substrate will not necessarily telegraph through carpet, it can affect the adhesive bond, so when in doubt give the floor a “skimcoat” with a good quality cementitious patching compound.  While you are checking the smoothness, check the porosity of the substrate as well because a porous substrate will soak up your adhesive. In cases like this a primer might be necessary. If it’s a concrete subfloor that is excessively porous, it could be a sign of other issues with the concrete itself.  The bottom line is that preparation is still an important part of the job so allow time to do it right.

Photo 4: These photos show why you should not assume carpet tile is immune to concrete moisture problems.  Always test for moisture! (Photos courtesy of Peter Craig)

As I have worked extensively in the area of trouble shooting and inspections, I have been involved in a large number of concrete moisture-related failures, and have shared a lot of those case studies here in “Let’s Talk Resilient.”   One of the common so-called “solutions” to a concrete moisture issue is to install carpet because it “breathes.” That is a fallacy.  Moisture-related problems with carpet are a big issue.  I am a part of the group working on the new ANSI S600 Carpet Installation Standard, and I can tell you there will be a lot in this new industry standard about concrete, moisture issues and the importance of testing. We are seeing more and more moisture-related failures with carpet and carpet tile. 

Photo 5: These photos show why you should not assume carpet tile is immune to concrete moisture problems.  Always test for moisture! (Photos courtesy of Peter Craig)

That being said, I am sure none will disagree that most carpet tile does not “breathe,” and as such you need to treat it just like a resilient floor as far as moisture.  In other words, test the concrete just as if you were installing sheet vinyl or any other so called “moisture-sensitive floor covering” material.  If you are not trained in the area of concrete moisture testing you need to be.  Get over to the archives on the FCI website ( and read up!

Adhesives for carpet tile are varied as are the methods for applying them.  In his December 2008 FCI article, “Acrylic Adhesive Basics,” Wally Giambastiani said it best:

The adhesives used for carpet tile installations are acrylic-based adhesives - these adhesives remain tacky after they dry which allows for the “releasable installation” of the carpet tile and are developed to have a low peel strength (easily pulled off the floor) and high shear strength (hold the tile from sliding). After installation, you can easily pull up the tile and replace with new tile.  During installation, and for this releasable feature to work properly, you must allow the adhesive to dry to the touch prior to installing the carpet tile (otherwise this becomes a permanent or non-release installation).  Please note that there are different pressure sensitive adhesives – it is your responsibility to know the type of carpet, carpet backing, and under what conditions the carpet is going to be installed and used. 

Wally also covered the importance of knowing what type of traffic conditions, environmental conditions and substrate conditions will be present before deciding what type of adhesive to use to install carpet tile.  Once you have this information through job site inspection, you’ll be able to determine how much floor prep is necessary and make the decision on which adhesive to use.

Photo 6: Application of spray adhesive can be a time-saving method, but care needs to be take to be sure the substrate is clean and smooth. (Photo by Christopher Capobianco)

Depending on all of these factors you may be working with an adhesive that is trowel applied, sprayed on, applied with a paint roller or a combination.  It may be a full-spread application, a partial adhesive application such as a “grid” pattern, a “self adhesive” carpet tile or a “loose lay” with no adhesive at all. The decision of which to use may depend on the job site conditions such as we mentioned above or it may come down to what the installer is comfortable with.  For example, spray adhesives are coming into major use in the industry - even for resilient flooring. We’ll cover spray adhesives in a future “Let’s Talk Resilient” column.  However, for a variety of reasons many installers are still more comfortable on their knees with a trowel, and there is nothing wrong with that.

 It is critical to use the right trowel when you go this route.  Carpet tile, like many resilient floors, is usually installed with a very thin bed of adhesive so too much can be a bad thing.  Less is better in most cases.  One of the advantages to using a trowel is that any debris or high spots in the floor can be observed as the trowel crosses the substrate and immediately corrected.   For a spray- or roller-applied adhesive, this feature is not present so it is absolutely critical to carefully look at the floor to see if there are any defects in the substrate.  One way to do this is to lightly pass a scraper across the floor.  Then, before starting with the adhesive you have to sweep and/or vacuum the floor and do it again before the adhesive is applied.  Take extra care to make sure the floor is flat and clean when you are using “non-trowel-applied” adhesives.

Laying out carpet tile is not that different from resilient floor tile.  Lay out the areas carefully and center the room as best you can to avoid border tiles that are less than six inches or so. Before spreading adhesive it is important to dry lay some of the tile because many carpet tile patterns are directional - and you will see arrows on the back of the tile.  If the tile is patterned, the designer or the owner may want it laid a particular way - either all in one direction or quarter turned.  Even non-patterned tile has a direction and if a “seamless’ look is preferred then all the tiles need to be installed the same way. However, quarter turning these tiles gives a totally different look.  There really is no right way or wrong way except that someone may have a preference, so it’s better to know this before you start. There also are a lot of applications where carpet tile is being used in patterns, borders, flash coving and other custom work and since many resilient installers have experience in this type of work, this presents an opportunity to show off your talent in a new material. But lay it out before you start and make sure that what you have in mind is the same as the owner or designer who chose the material.

The actual installation of carpet tiles needs to be snug up against any walls or fixtures, especially with “loose lay” or “self adhesive” tiles.  I inspected a job last year that had major gaps in the tile in some areas.  When I looked under the baseboards I found that the tile was tight up against the wall.  However, it was not installed that way!  The installer left a gap around the edges and the tile shifted once it was exposed to traffic.  I had this same experience in my own office when I installed carpet tile.  Because of some pending construction I was not able to finish the floor right up to one wall and sure enough the tile “walked,” creating little gaps that I periodically adjust.  Luckily the construction is getting done this spring so I will get this job done at last.  What is that old saying about the shoemaker whose children don’t have shoes?

 I think the growing popularity of carpet tile presents a challenge for installers to put to good use what they know abut the very challenging and technical field of resilient floor installation.  It’s a world of opportunity for more work and more ways to show off their craftsmanship.